Immunoassays continue to remain the major backbone of diagnostic industry and the most conventional of these include ELISA. Though in use from decades now, ELISA still continues to be a major support for diagnosis of infectious conditions. With the advent of dedicated commercial kits comprising of controls as well as calibrators, the sensitivity of the technique has increased manifold.
Principle of Enzyme Linked Immunosorbent Assay (ELISA)
ELISA in an immunoassay which majorly deals with analyzing antigen-antibody complexes using enzyme labeled antibodies in a 96 well microtitre plate. The commercial plates are pre-coated with specific antigens, and on addition of patient serum, antibodies if present against the antigen, will bind and form immune complexes. Post incubation and washing, a secondary labeled antibody is added, followed by substrate to aid in color development. The intensity of the color can then be measured using an ELISA plate reader.
The main advantage of this technique involves, its versatility to be designed and used for multitude of infections diagnosis. The tests can also be performed both in qualitative as well as quantitative fashion requiring simple instruments.
ELISA is generically a manual technique involving requirement of technical skills for a workflow with precision. For decades being performed manually, albeit using commercial kits, analyzers to provide automation solution for ELISA have also now become available in the market. Thyrocare is one of the few laboratories to have added such automations to its ELISA floor. These include:
- Dynex- Merilyzer
- Chorus TRIO [Diesse]